Electrical heater



(No Model.)

J. V. CAPEK. ELECTRICAL HEATER. No. 424,921. Patented Apr.

INVENTOR U ITED STATES PATENT OFFICE.

J OllN CAPEK, OF NE\V YORK, N. Y., ASSIGNOR 'IO HIMSELF, AND EDVARD H. JOl INSON, OF

ELECTRICAL H EATER.

lrREENVICIl, CONNECTICUT.

SPECIFICATION forming part of Letters Patent No. 424,921, dated April 1, 1890..

' Application filed October 26. 1889. Serial No. 328,271. (No model.

To all whom it may concern.-

Be it known that I, JOHN V. CAPEK, aeit-izen of the United States, residing at New York city, in the county and State; of New York, have invented a certain new and useful Improvement in Electrical lIeat-crs, of which the-following is a specification. In my patent, No. 395,950, dated January 8, 1889, is set forth a form of electrical heater consisting of a widely-diffused and very thin body of electrical conducting material placed upon the walls of a room or on any other large surface and arranged to be heated to a comparatively low temperature, the conducting material mereespeeially set forth being graphite. This arrangement of spreading a carbon surface over the walls of a room has been found undesirable in some situations,

for the reason that it interfered with deco- -1'ation and ornamentation of the walls, and

because in many places the walls of a room are so brokenby doors, windows, &c., that a continuous heating-surface cannot be produced.

The object of my'present' invention is to provide an electrical heater of an economical and effective character which shall have all the advantages of the form of heater set forthin the patent above referred to,,but in which the heating-surface shall be concentrated so as to occupy only a small space,"and so that placed in any convenient To this end I provide an electrical heater which consists of thin strips of insulating material, each of which is covered on both sides with a thin coating of conducting material-such as earbon-such strips being piled one upon another, separated by suit- .tional area is formed..

able insulationand by air-spaces, and the strips being electrically connected together at alternate ends, so thata zigzag conductor of considerable length and, smalleross-sec- These heating-strips are preforably'placed in a suitabloopen or perforated box'or inclosed in a case, which may .be placed. under the floor of a room or set into thowall, or supported against the suitable and convenient way. The strips may h of any suitable insulating material, such as paper or pasteboard'or thin wood. These combustible materials may be used because it is not designed that the'temperature of the heater shall be raised to a degree higher than the igniting-point of such materials, the necessary heat beingobtained by the large radiating-surface which is provided; butin order to guard against danger of fire most effectively I prefer to employ 'a non-combustible insulating material, and more especially I prefer to use asbestus; I

In constructing the heaterI takea suitable number of the 'asbestus or other strips covered with carbon, and I cover their ends with thin metal, preferably by wrapping such ends with tin-foil. I then v another, placing between them at each end a small block of asbestos; or other suitable insulating material, alternate blocks of ashes tus at each end being covered with metal or wrapped with tin-foil. By this means alternate strips are connected together at their ends. I also wrap a strip of asbestus around each end of the pile of strips and secure the same by abinding of wire at each end. Previous to-this, however, I insert at the ends of the strips where the external connections are to be made a thin metal strip, which is held between the end of one of the heating-strips and the tin-foil wrapped upon such end.

As stated,I prefer to use powdered graphite for the carbon covering of the strips. Such material may be applied to paper and like material by rubbing the graphite upon the paper, the paper or the graphite being preferably slightly moistened before rubbing. I have found, however. that the material may be morereadily applied by moistening the paper with a sticky solution such as a solution of sugar or chromic'acid-- and then rubbing the graphite upon the paper. With asbestus', however, this method cannot be readily employed, because when the asbestus is rubbed .the surface is rubbed off and destroycd. 'lo obviate this I first soak the asbestus in a solution of a, substance which will fill up the pores of theasbestus so as to make a stronger and harder strip. After the material has become dried Igraphitize it, as. described. I may soak the asbestos 5 pile such strips one upon and solidify,

' current with whi with such materials as glue, varnish, a solution of sugar, or (-hroinie acid. I have found the last two materials most satisfactory for the purpose. This hardened asbestus forms a particularly effective material for carrying the conductor in elect riral'heaters, it beingof Sutlicient strength and hardness, a good electrical insulator, and non-inflammable.

in my patent bet'ore referred to the graphite was applied on one side only ot the carryingstrips. in my present invention I graphitize the strips or plates on both sides, whereby I give double the heating capacity in the same space and with the same amount of inactive supporting material.

The above may be more readily understood by reference to the accompanying drawings.

Figure 1 illustrates a heater embodying my invent-hm, the same being shown in perspective and as supported on a bracket on the wall. Fig. 2 is a cross-section of the heater placed under the floor; Fig. 3, a longitudinal compactly arranged such arrangement has also the advantages adjacent plates,

vertical section of the heater, and Fig. l a longitudinal vertical sect-ion of a part of one of the heating-strips upon a much exaggerated scale.

Referring first to Figs. .3, '3, and l, thin strips (1, of asbestus treated in the manner described, are thinly covered on both sides with coatings b of powdered graphite. A suitable number of snchst rips are put'togct-hcr side by side, as shown in Figs. 2 and 3, with blocks 0 of asbestusbetwcen, their ends being wrapped with tin-toil :1. Alternate blocks of sbestus at each end are also wrapped with tin-foil 6,- so that at these points electrical connection is made between the ends of adjacent strips, whereby all the strips are joined together in series and a zigzag conductor of high resistance is formed, through which the current flows, as indicated by the arrows in Fig. 3. Connection may be made to the ends of the series by thin strips or wires f, inserted between the ends of the outer strips and their tin-foil coverings. Around each end of the bundle of strips is wrapped a strip of ashestus 9, such wrappings being secured by tight bindings of wire 70... Y

The complete heater is shown in Fig. 1 placed inside aibox or bracket A, hung on the wall of the room and having an open 'or perforated front.

In Fig. 2 the heater is supported in a pocket or case B, placed under the floor and lined withasbestus U and covered with a perforated lid or cover l).- It is evident that the heaters may be arranged or disposed in any other suitable and convenientmannorbcsidcs those shown. It is also evident that any'desired number of heaters can be placed in a room, and also that, if desired, two or more heaters may be placed in the same open inclosin gcasc, such heaters being connected in multi plc are or in series with each other, or in multiple series, according tothc character of tho 11 they are used. In any ing visible,

'by the heater from any cause of thin strips of electrical case prefer to so proportion the resistance and radiating surface of the heaters withregard to the current that their temperature will not be raised to a point higher than the igniting-point of ordinary combustible materials, so that the heaters may be placed wherever desired without danger of fire. "his, however, is not absolutely essential, since the supporting parts of the heater are non-combustible material, and such heater may be placed so as .to be surrounded entirel y by such material.

It will be seen that by arranging the heating-strips in the manner set forth I get 'a high resistance and a large radiating-surface very in a small space, and

that the structure has considerable strength, although theindividual strips are very thin, that each plate protects the surfaces of the so that, if desired, any external protection may be done away with, and that the surfaces of the plates, whose dark color would be obj cctionable in many places, are hidden, only the edges of the plates beand such edges may be bronzed or otherwise ornamented, so that the heater can be placed anywhere and may become an ornament rather than a disfigurement to the place.

. The manner tween the ends of. the plates .is an exceed ingly simple and effective one, wher'tin-foil is used, as I prefer. Tin-foil does not readily oxidize. It is cheap and is very easily applied, and in addition its melting temperature isvery low, being lower than the igniting-point of most combustibles, and it therefore furnishes protection from fire, since if adarngerous temperature is attained the tin-foil connections will melt and break the circuit. Vhat I claim is-- '1. In an electrical heater, the combination of thin electrical conducting-strips secured together and facing one another and pieces of insulating material, interposed between said strips at their ends, the middle portions of said strips being separated by air-space, substantially as set forth.

2. In an electrical heater, the combination of thin strips of electrical insulating material covered with a coating of conducting mate rial and secured together side by side and separated by insulating material and airspace, substantially as set forth. V

3. In an electrical heater, the combination insulating material covered on both sides with a coating of conducting material and secured together side by side and separated and air-space, substantially as set forth..

4. As a heating resistance -for electrical heaters, a strip of hardened asbestos coated with graphite, substantially as set forth.

especially by insulating material- IIC 5. As a. heating-resistance for electrical heaters, a strip of asbe'stusIcoated or impreg- 6. In an electrical heater, the combination of strips of asbestus covered with thin coatings of electrical conducting material and secured together side by side and separated by insulating material and air-space,substantially as set forth.

7. In an electrical heater, the combination of strips of asbestus covered with thin coatings of graphite and secured togetherside by side and separated by insulating material and air-space, substantially as set forth.

8. In an electrical heater, the combination, of thin' electrical conducting-strips secured together and facing one another, pieces of insulating material interposed between. said strips at their ends, the middle portion of said strips being separated by air-space, and

electrical connections between the strips at alternate ends of the bundle, whereby all the strips are connected in series, substantially as set forth.

9. In an electrical heater, the combination of conducting-strips placed side by sidc aml blocks of insulating material between the stripsat their ends, alternate blocks being covered with conducting material, substantially as set forth.

10. In an electrical heater, the combination,

with conductingstrips having their ends wrapped with metal and placed side by side, of insulating-blocks between their ends, alternate blocks being wrapped in metal, substantially as set forth.

This specification signed and witnessed this 30th day of August, 1889.

' JOHN V. CA'P EK.

it/1188868: D. I'L'DRISCOLL,

WILLIAM PELZER. 

